Vehicle front body structures generally include a pair of laterally spaced front side frames extending in a longitudinal direction of the vehicle, and right and left front wheels disposed on lateral outer sides of the respective front side frames. A particular example of such vehicle front body structures is disclosed in Japanese Patent Laid-Open Publication (JP-A) No. 8-108865.
The disclosed vehicle front body structure, as shown in FIG. 9A hereof, includes left and right front side frames 201 (only left one being shown) extending in a longitudinal direction of the vehicle with a combined engine-and-transmission unit 205 disposed between the left and right front side frames 201. Left and right front wheels 206 (only left one being shown) are disposed on lateral outer sides of the respective front side frames 201. Each of the front side frames 201 has a pair of vertically spaced ribs or beads 202 and 203 extending in a longitudinal direction of the front side frame 201 to reinforce a part of the front side frame 201 to thereby control a buckling strength of the front side frames 201.
As shown in FIG. 9B, the beads 202, 203 are formed on each of an outer sidewall 207 and an inner sidewall 208 of the respective front side frames 201. The beads 202, 203 projects into an internal space of each front side frame 201 but the beads 202, 203 on the outer sidewall 207 are laterally spaced from the beads 202, 203 on the inner sidewall 208. Although the beads 202, 203 are disposed on a portion of each front side frame 201 which corresponds in position to a front upper part of the corresponding front wheel 206, there is no disclosure or teaching in JP 8-108865A that the aforesaid front side frame portion is recessed to allow swivel movement of the front wheel. The beads 202, 203 can reinforce the front side frames 201 to a certain extent but the reinforcing effect attained by the beads 202, 203 are found to be insufficient in the case where a recessed wheel relief portion is provided in each front side frame.